Boat propulsion and steering apparatus



1964 A. B. PETRlCH 3,159,132

BOAT PROPULSION AND STEERING APPARATUS Filed June 15, 1962 INVENTOR. I4LLEN 8 PETE/CH flrrok/vw United States Patent 3,159,132 BOAT PRGPULSION AND STEERING APPARATUS Allen B. Petrich, 2809 Garfield Road, Tacoma, Wash. Filed June 15, 1962, Ser. No. 202,779 2 Claims. (Cl. 114-162) This invention relates to improvements in boat propulsion and steering apparatus. More particularly it relates to improvements in the mounting and construction of the rudder for boats such as work boats, pleasure boats and the like and in its relationship to the particular propeller with which it is associated and also to the particular relationship of propeller and rudder to the adjacent surfaces of the boats hull and to each other for the pur pose of providing a more satisfactory operational performance of the boat.

Specifically stated, the present invention resides in the improvements in the rudder assembly as applied to the boat including the application of rudder post mountings to the transom of the boat and in the particular relationship of the rudder to the propeller and of the propeller to the boat.

It is the primary object of this invention to provide improvements in rudder construction and in rudder and propeller relationship that eliminates cavitation about the rudder; that provides better boat steering control and reduces to a minimum the vibration and noise that is usually produced by the operation of the propeller when positioned in the present day conventional manner.

Further objects and advantages reside in the provision of means for and manner of mounting the rudder post that reduces to a minimum the possibility of damage to the boat in the event of the rudder striking an object in the water.

Still further objects and advantages of the invention reside in the details of construction of the various parts embodied in the combination; in the combination and relationship of parts and in their mode of use, as will hereinafter be fully described.

In accomplishing the above mentioned objects and advantages, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a perspective view of the stern portion of a boat showing the improved rudder of this invention and its mountings as applied to the transom.

FIG. 2 is a vertical section taken in the longitudinal direction of the boat, through the bottom and transom, showing the relationship of the propeller and rudder and the rudder mountings and their positioning on the hull.

FIG. '3 is a horizontal section substantially on line 33 in FIG. 2. I

FIG. 4 is a cross-section of a portion of the rudder taken on line 4-4 in FIG. 3.

FIG. 5 is a sectional detail of the mounting bearing containing the upper end portion of the rudder post and a part of the steering lever attached thereto.

Referring more in detail to the drawings:

In FIG. 1, designates generally the rear or stem end portion of a boat with which the present invention is embodied. It is best shown in FIG. 2 that the boat has a bottom 11 and a transom 12. Also, in FIG. 2,

13 designates a propeller mounted on a propeller shaft 14 extending from a suitable source of power, not herein 3,159,132 Patented Dec. 1, 1964 The rudder embodied by the present invention is designated in its entirety by numeral 18 and it is mounted by a vertical rudder post 19. This post is rotatably contamed at its upper end in a bearing 20 and at a point closely adjacent the rudder it is rotatably supported in a bearing 21 that is formed at the rearward end of a bracket 22. On a single propeller boat, the bearing 29 and bracket 22 are fixed to the rear surface of the transom in the central, vertical, longitudinal plane of the boat. At its upper end, the rudder post 19 is equipped with the usual quadrant tiller 25,that extends inboard of the transom through an opening 26 may be interconnected at its forward end with the usual tiller ropes or with other rudder controls, not shown. In the event that twin propellers or screws are employed, each propeller would have a comparable rudder assembly wherein each rudder is directly astern of its respective propeller.

Ithas been shown in FIGS. 2 and 5 that the bearing 20 is cast integral with a housing 27 and the housing is flanged for its fixed securement by screws or bolts 28 to r the transom 12. The bracket 22 which carries the bearing 21 is also flanged for its fixed securement in a similar manner to the transom and is ribbed for additional strength and rigidity.

One of the important features of this invention resides in the details of construction of the rudder. The relationship of the rudder to the propeller is also important to obtain the most satisfactory and vibration free operation of the boat. It is to be observed, particularly by reference to FIG. 2, that the rudder comprises a rudder plate 18 of substantial vertical extent. The rudder is positioned immediately rearward of the propeller 13 and the height dimension of the effective body portion is equal to propeller diameter. Across its top edge, the plate 18p is formed with an integral, horizontal flange 18 of substan tial width across its forward portion from which it is tapered along opposite edges to a rounded point at the rear vertical edge of plate 18p. It is shown in FIG. 3 that the forward end of flange 18f is formed in an arcuate curve that is centered in the central longitudinal line of the post 19. FIG. 4 shows the flange 181 to be formed lengthwise along its central line with m upstanding rib 30. The particular construction and relationship of the parts is such that the flange 18] is a cavitation plate which substantilaly reduces the cavitation of the water caused by driving action of the propeller and thereby provides a more efi'icient and quieter operation.

Numerous advantages are inherent in the construction and relationship of the present several elements. The disposition of the rudder rearwardly of the transom is substantially greater than in normal construction'and this permits the disposition of the propeller at a location that lessens, to a great extent, the usual propeller vibration and noise. Furthermore, the horizontal flange 18 of the rudder operates to prevent cavitation about the rudder plate 18p with improvement in the steering property. The mounting of the rudder post in the two bearings that are spaced at substantial distances apart gives substantial rigidity to the rudder mounting and permits placing the opening for the tiller at distance substantially above Water line so as to provide insurance against flooding of the hull that would result from leakage through the opening or in the event the rudder strikes an object in the water and the housing is torn from the transom. A further advantage of the construction and relationship of parts is that it permits the engine to be moved further af-t than in present day propeller and rudder assemblies.

What I claim as new is:

1. In a boat having a bottom with transverse rear edge, a transom joined with said rear edge and directed upwardly therefrom, a plurality of vertically aligned supporting bearings fixed to the rear surface of said transom, a vertieally disposed rudder post upper supporting bearing being secured to-the transom substantially, above the normal water line of the boat, steering means connected to said rudder post above said upper supporting bearing, a rudder. plate mounted at the lower end of said rudder post rearwardly of the plane of said transom and extending 'below the level of the rear edge of the boat bottom, a propeller mounting drive shaft supported from the boat bottom and a propeller mounted on said drive shaft immediately forward of the rudder plate and substantially in vertical alignment With the transom at its juncture With the bottom.

2. A combination according to claim 1 wherein said rudder plate extends rearwardly from the axial line of mounted by said bearings, the

the rudder post and has a vertical depth substantially equal to the diameter of the propeller and is supported at the level of the propeller and said rudder is formed along its top edge with a horizontal flange that extends a'substantial distance on opposite sides of the rudder plate.

References Cited -in the file of this patent UNITED STATES PATENTS 1,515,024 Flettner Nov. 11, 1924 1,795,346 Rebl Mar. 10, 1931 1,858,582 Fahrney May 17, 1932 2,528,755 Johnson etal. NOV. 7, 1950 

1. IN A BOAT HAVING A BOTTOM WITH TRANSVERSE REAR EDGE, A TRANSOM JOINED WITH SAID REAR EDGE AND DIRECTED UPWARDLY THEREFROM, A PLURALITY OF VERTICALLY ALIGNED SUPPORTING BEARINGS FIXED TO THE REAR SURFACE OF SAID TRANSOM, A VERTICALLY DISPOSED RUDDER POST MOUNTED BY SAID BEARINGS, THE UPPER SUPPORTING BEARING BEING SECURED TO THE TRANSOM SUBSTANTIALLY ABOVE THE NORMAL WATER LINE OF THE BOAT, STEERING MEANS CONNECTED TO SAID RUDDER POST ABOVE SAID UPPER SUPPORTING BEARING, A RUDDER PLATE MOUNTED AT THE LOWER END OF SAID RUDDER POST REARWARDLY OF THE PLANE OF SAID TRANSOM AND EXTENDING BELOW THE LEVEL OF THE REAR EDGE OF THE BOAT BOTTOM, A PROPELLER MOUNTING DRIVE SHAFT SUPPORTED FROM THE BOAT BOTTOM AND A PROPELLER MOUNTED ON SAID DRIVE SHAFT IMMEDIATELY FORWARD OF THE RUDDER PLATE AND SUBSTANTIALLY IN VERTICAL ALIGNMENT WITH THE TRANSOM AT ITS JUNCTURE WITH THE BOTTOM. 